Combined starter and engine control mechanism



Oct. 6, 1964 H. B. TILLOTSON ETAL 3,151,605

COMBINED STARTER AND ENGINE CONTROL MECHANISM Filed Sept. 7, 1961 2 Sheets-Sheet l INVENTORS HENRY B.TILLOTSON By VERNON J.WORREL Maw Oct. 6, 964 H. B. TILLOTSON ETAL 3,151,605

comemso STARTER AND ENGINE CONTROL MECHANISM Filed Sept. 7, 1961 2 Sheets-Sheet 2 INVENTORS HENRY a. TILLOTSON y VERNON J. WORREL United States Patent 3,151,665 CGMBE ED STARTER AND ENGINE CQBN'IRQL M'ECHWdP/l Henry B. Tillotson, Minneapolis, and Vernon J. Worrell, St, Paul, Minn, assignors to Turn Manufacturing Cor poration, Minneapolis, Minn a corporation of Minnesota Filed Sept. 7, 1961, Ser. No. 136,435 7 (Cl. 123-175 This invention relates to starters for small size gasoline engines, and more particularly, to a control arrangement that permits starting such an engine from a remote position.

For many years, it has been the practice to start small size gasoline engines on devices such as powered lawn mowers by pulling on a handle that is connected to a short length of rope so as to turn the crank shaft of the engine snfiiciently to cause the engine to start running. The force exerted on the handle, in addition to starting the engine, conventionally winds a spring which is then effective, upon release of the handle, to withdraw the length of rope into the housing of the starter mechanism and cause it to be recoiled around a drum located therein. Thus, this type of starter is commonly known as a ecoil starter.

More recently, it has become commonplace to elimimate the rope and recoil mechanism, and substitute a hinged handle that is turned, or cranked, by the operator in order to wind a flat coil spring located Within the housing of the starter mechanism. The engine is then started by operating a trip lever which is normally mounted on the starter housing, and this in turn removes a mechanical stop and permits the coiled, or woundup, spring to turn the crank shaft of the engine sufficiently to cause it to start. In view of the sudden application of energy to the starting function, this type of starter mechanism has become commonly known as an impulse starter.

The running characteristics of the small size engines here under consideration are normally controlled by a single lever mounted on the engine housing, which is slideably moveable for continuous throttle control be- Ween two limit positions. When the lever is moved to the first of said limit positions, an insulated terminal post connected to the spark plug of the mower is contacted by the throttle control lever, and the lever is thereby edectiv-e to ground this terminal post and pre- 'vent the engine from starting, or terminate the operation or" the engine if it is already started. When the lever is moved to the second limit position, a connected linkage is effective to choke the engine in a conventional manner, and it is almost invariably necessary to move the ever to this second position in order to start the engine. As the lever is moved from said first limit position to said second limit position, with the engine running, the engine speed is con nuously increased until the maximum speed, or full throttle, position is reached immediately adjacent the point at which choking of the engine begins. There after, continued movement of the lever through a relatively short range causes choking to increase until full choking occurs at the second limit position.

The normal procedure for starting an engine having controls of the type described, is to move the throttle control lever to the second limit position, then operate the starter, and then assuming the engine has started, quickly move the control lever to a suitable running position before the engine is choked on This hecomes somewhat troublesome when an impulse starter is used in combination with a control device located remotely from the engine, such as on the handle of a lawn mower. When such a remote control is used, a hand lever is normally provided which can be moved in exact correspondence with the throttle control lever, through use of a standard flexible control cable connected from the hand lever at the remote location (such as on the upstanding handl of the mower) to the throttle control lever mounted on the engine. However, when this arrangement is used with an impulse starter, the operator must move the hand lever to the second limit, or choke position, then wind the starter spring through use of the hand crank, then operate the trip lever to start the engine, and then move quickly back to the remote hand lever and move this lever to an appropriate running position before the engine is choked out.

This procedure subjects the operator to substantial haard and inconvenience when starting the engine. When he is winding the starter of a rotary lawn mower, for example, if the trip lever is accidentally operated, the engine could start unexpectedly and cause serious injury to the operators feet or hands if they are near the cutting blade. Furthermore, the inconvenience or moving quickly back to the handle when the engine starts, in order to move the hand lever to an appropriate running position, cause the operator to be careless and subject himself to unnecessary injury.

Efforts have been made to eliminate these problems through the use of separate control cables, including a separate cable for the starter trip lever, to permit remote operation thereof. However, this adds to the total expense of the control system, and makes it necessary for the operator to use two levers at the remote location when starting the engine.

Thus, it is an object of my invention to provide an inexpensive control mechanism for a small gasoline engine having an impulse starter, which permits the engine to be started conveniently and safely from a remote position.

A further object or" the invention is to provide such a control mechanism with a linkage that enables the remote hand lever to be in the first limit, or stop, position when winding the spring of the starter assembly.

Another object of the invention is to provide a control arrangement of the type described wherein a single remotely controlled hand lever of the standard type is effective to provide all of the desired control functions.

Other objects and advantages of the invention will become apparent from the following description of a preferred form thereof, and the two sheets of drawings illustrating the form, in which:

FIGURE 1 is a perspective view of a portion of a small gasoline engine, and

FIGURE 2 is an exploded perspective view of the starter mechanism.

In FIGURE 1, we have shown a portion of a gasoline engine 13, having a shroud 11, with a starter mechanism 20 located at the top thereof. Our novel control linkage 33 is located to one side of the starter mcch anism and near the top'of the motor shroud 11 as shown,

. 3 and this linkage is shown connected thl'Ough a flexible cable 54-55 to a remote hand control device 50. A few of the elements of the throttle mechanism of the motor, item 60, as are necessary to a full understanding of our invention, are shown along the lower side of the portion of the engine illustrated.

In order to have a full understanding of our invention, it is necessary to have a general idea of the starter operation, and we have therefore shown an exploded view of starter 20 in FIGURE 2. This starter mechanism includes an outer housing 21 which is securely attached to the engine by means of bolts fastened through openings 77. Outer housing 21 is provided with an integral hub 74 centered at the top thereof as shown, said hub 74 having a bore 75 through the center thereof, with a slot 73 machined along one side of said bore.

The handle located immediately above outer housing 21 includes knob 13 mounted on member 12 and member 12 is mounted to member 70 through hinge 14. Shaft 71 of the starter mechanism is securely attached to the underside of handle member 70, and extends down into the starter mechanism when the handle is in the normal operating position with handle member 78 located around a portion of hub 74, so as to be rotatable therearound.

Inner-housing 80 of the starter mechanism is mounted within outer housing '21 and is rotatable therein. Innerhousing 80 is provided with an integral hub 81 which has teeth 83 on the outer edge to form a ratchet, and is formed with a center bore 82 as shown. Center bore 82 receives shaft 71 with a snug fit, and is securely attached to said shaftby means of a key or other standard fastening means (not shown). When the starter is assembled, hub 81 is positioned within bore 75 of hub 74, and pawl 72 is located in slot 73 and tensioned against teeth 83 by means of a suitable spring (not shown). Thus, it should be noted that the handle can only be rotated clockwise as viewed from the top, since the wedge-shaped end of pawl 72 engages the teeth 83 on hub 81 and prevents counter-clockwise rotation of the handle and inner-housing.

Coil spring 86 fits within inner housing 80 and is provided with a flange 88 which fits within slot 84 in the side wall of inner housing 80 and against edge 85 thereof. The other end of spring 86 is formed into loop 87 as shown, and with hub 92 in its normal position within the center of spring 86, loop 87 is tensioned against the outer surface of hub 92 by the natural resilience of spring 86. Hub 92 is formed as an integral part of starting plate 99, and is formed with a central bore 93 and three outer flanges 94 as shown. Bore 93 is sized to permit free rotation of starting plate 90 on shaft 71.

With the arrangement of parts as shown, if starting plate 90 is prevented from rotat ng with respect to outer housing 21 and the engine shroud, the clockwise rotation of handle 12 causes clockwise rotation of innerhousing 80, and spring 86 is thereby wound-up between edge 85 of the inner-housing 80 and one of the flanges 94 on hub 92. It should be noted that spring 86 cannot be wound-up to the point of breaking, since loop 87 would merely jump from flange to flange around hub 92 as the tension becomes too great.

After the coil spring 86 has been wound-up in the manner described, it can be unwound by releasing starting plate 90 and permitting its rotation with respect to outer housing 21. Coil 87 of spring 86 then imparts a rotary motion to plate 90, so as to cause clockwise rotation thereof until spring 86 has become relaxed. This sudden rotation of plate 90 causes ratchet 97 to pivot within a slot of flange 95 under the influence of the centrifugal force thereby created. Thus, the rectangular end of ratchet 97 is moved outwardly against the force of spring 96, and is effective in its outwardly extended position to engage the internal teeth 181 of hub connected to the upper end of the engine shaft 182. Ratchet 97 thus transmits the force of spring 86 to shaft 182; and

causes the engine to start, and when spring 86 becomes relaxed and the rotation of plate 90 is thereby terminated, spring 96 pulls ratchet 97 out of engagement with teeth 191 so as to remove all operative connection between the motor and starter during normal running of the engine.

It should be noted that nut 76 is provided to permit assembly of the starter mechanism and attaches to the lower end of shaft 71 so as to hold the elements of the starter mechanism in proper operating relation with respect to one another. 7

It should also be noted that the rotation of handle 12 does not wind spring 86 when starting plate 90 is not held from rotating, since plate 90' and inner-housing merely rotate as a unit. 7

The rotation of starting plate 90 is controlled through trip levers 40 and 41 which are rotatably mounted at openings 42 and 43 to opening 45 in outer housing 21, by means of a rivet 44. Spring 46 is attached between outer housing 21 and lever 41 as shown and is normally effective to move lever 41 in a counter-clockwise direction about opening 43 so as to move flange 47 to within the vertical confines of housing 21. When in such position, flange 47 engages the leading edge of one of the flanges 91 on starting plate 90, and thereby prevents rotation of plate 90 with respect to housing 21. Thus, flange 47 is etfective to condition the starting mechanism for the wind-up operation of spring 86.

Trip lever 40, which is freely rotatable with respect to trip lever 41, is located beneath lever 41 and with flange 49 adjacent to extension 48 of trip lever 41. Thus, when lever 44) is moved in a clockwise direction, flange 49 engages extension 48 and moves lever 41 and flange 47 out of engagement with flange 91 of plate 90. This control movement is provided through opening 37 in flange 40, which will now be described in connection with FIG- URE 1.

It should be noted that opening 37 in trip lever 40 is connected through wire link 36 to opening 35 in operating lever 31. Thus, when the upper end of operating lever 31 is moved counter-clockwise about pin 34, the link 36 is effective to move trip levers 40 and 41 so as to permit rotation of starting plate 90. Operating lever 31 is securely attached to the upper end of pin 34 and the lower end thereof is securely attached to follower arm 38. Pin 34 is positioned by bracket 39 and is freely ro- V tatable in flange openings thereof as shown. Thus, movement of throttle control lever 61 is transmitted to trip lever 41 through control linkage 39 including elements 31, 33, 34, and 36. 7

Throttle control lever 61 is connected to hand lever 52 of remote control 50 through control wire 54 of flexible cable 54-55. Tubular member 55 of cable 54-55 is connected at the motor end by a bracket 57, and at the remote control housing 51 by a bracket 56 as shown. Thus, as control wire 54 is moved with respect to housing 51 through connection 53 and movement of handle control lever 52, a corresponding movement is imparted to throttle control lever 61 in the normal manner.

It should be noted that hand control lever 52' and throttle lever 61 are shown in the second limit, or full choke, position (wire link 62 being effective to control the choking function in the usual manner) and control linkage 38 is positioned so as to hold trip lever 40 and flange 49 thereof against trip lever 41, and thereby hold flange 47 of trip lever 41 out of engagement with the flanges 91 of plate 90. The mechanism is, therefore, conditioned to prevent winding coil spring 86 in starter mechanism 29. In order to wind the spring, hand lever 52 is moved to the position shown in dotted lines, thereby moving throttle control lever 61 to the first limit, or stop, position, which in turn causes the movement of flange 47 into engagement with flanges 91 of starting plate 96. The operator can then wind spring 86 by folding the handle 12 to the extended position, and cranking the handle in the usual manner. It should be noted that even if campus something were to go wrong with the control linkage at this point, and the spring would happen to rotate the drive shaft of the engine, the engine could not start since the spark plug (not shown) would be shorted through insulated terminal 63 which would be in contact with and grounded through throttle control lever 61.

To start the motor, after the spring has been tensioned, the operator moves to the remote location, and moves handle control lever 52 to the full forward, or full choke, position. The throttle control lever is thereby moved to the full choke position, choking the engine through link 62 in the usual manner. Starting of a small gasoline engine of the type herein described can only be effectively accomplished when the engine is choked, and this movement is necessary during the starting of the engine. It should be noted that as throttle control lever 61 is moved away from the stop position, wire link 36, and flange 49 of trip lever 40, are effective to pull flange 47 against the force of spring 46 out of engagement with flange 91, and the motor then starts as above described. The actual point at which flange 47 clears and thereby releases flange 91 may vary for difierent applications, and could logically occur at numerous points in the throttle or choke ranges. However, we have found it desirable for this application to have the release occur when throttle control lever 61 is at the maximum, or full, throttle position. This actual point of release is not of significance to the operator, since he ordinarily moves handle 52 very quickly past the specific point where release occurs, and into the full choke position, to facilitate engine starting. The operator would then be holding handle 52, and merely moves it back to a normal running position to operate the engine in the desired manner.

The starter mechanism will, of course, stop rotating almost immediately after the engine starts, and it is possible that starting plate 90 could stop rotating with one of the flanges 91 positioned adjacent to flange 47 of trip lever 41, so as to prevent lever 41 from moving counterclockwise and into engagement with one of the flanges 91. The remote control device can, however, be positioned to short out the sparkplug and stop the engine. Trip lever would move somewhat further in a counter-clockwise direction during this stopping operation than trip lever 41, thereby moving flange 49 out of engagement with extension 48 on lever 41. However, when the engine is cranked for the next starting operation, the initial movement of handle 12 causes rotation of starting plate 9%) and thereby moves the flange 91 away from flange 47, permitting spring 45 to move trip lever 41 into the normal starting position. Continued rotation of the handle would then move starting plate fit and carry another of the flanges 91 into engagement with flange 47 on trip lever 41, conditioning the starter mechanism for the next starting operation.

It should be noted that an additional opening 22 has been provided in outer housing 21, of the starter assembly 21), with a corresponding hole 23 in trip lever 41. These two openings are aligned when control linkage 38 is positioned as shown so that a pin (not shown) may be used to securely fix trip lever 41 in a position where flange 47 is out of engagement with flanges 91 of starting plate 99. Thus, when a pin is used in the intended manner, the engine cannot be started, since the rotation of handle 12 would t en be ineffective to tension spring 86.

While there has been described what is at present considered to be the preferred embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention and it is, therefore, aimed in the appended claims to cover all such modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. A control mechanism for an impulse started gasoline engine, wherein said engine includes a throttle control movable between stop and choke positions and wherein said starter includes a rotatable starting plate, a coil spring,

and a spring tensioning device comprising: a release lever rotatably mounted on said engine and effective in one position to engage said starting plate and prevent the rotation thereofduring the operation of said spring tensioning device; and a control linkage operatively connected between said throttle control and said release lever, said control linkage being effective to position said release lever at said one position when said throttle control is in saidstop position, movement of said throttle control from said stop position being effective to operate said control linkage, which in turn operates said release lever out of engagement with said starting plate, said tensioned spring being then effective to cause said starting plate to rotate and start the engine.

2. A control mechanism for an impulse started gasoline engine, as claimed in claim 1, further comprising a lever operatively connected to said throttle control and movable between first and second limit positions corresponding to said stop and choke positions, respectively.

3. A control mechanism for an impulse started gasoline engine, as claimed in claim 1, wherein said release lever includes first and second trip levers mounted so as to be relatively movable, said first lever being operatively connected to said control linkage and shaped to bear against said second trip lever and .cause the movement thereof as said throttle control is moved toward said choke position, and resilient means eflective upon movement of said throttle control toward said stop position to move said second trip lever into engagement with said starting plate.

4. A control mechanism for an impulse started gasoline engine, as claimed in claim 3, wherein said second trip lever is shaped to permit the locking thereof with respect to the said engine in a position which prevents said second trip lever from moving into engagement with said starting plate and thereby prevents the tensioning of said spring.

5. A control mechanism for a spring-started gasoline engine, wherein said engine includes a throttle control movable between stop and full choke positions and wherein the engine starting mechanism includes a spring, starting means for rotating the crank shaft of the engine, and means for tensioning said spring, comprising: first control means mounted on said engine and operatively connected between said throttle control and said starting means, effective with said throttle control in said stop position to engage said starting means and prevent the rotation thereof whereupon operation of said tensioning means is eflective to tension said spring against said starting means, and effective when said throttle control is moved away from said stop position to release said starting means whereupon said tensioned spring is effective to rapidly rotate said starting means and crank shaft and thereby start the engine; a hand lever operable between first and second limit positions; and second control means operated by said hand lever to cause corresponding movement of said throttle control between said stop and full choke positions as said hand lever is moved between said first and second limit positions, respectively.

6. A control mechanism for a spring-started gasoline engine as claimed in claim 5, wherein said first control means includes a pair of trip levers mounted so as to be relatively movable, one of said levers being shaped to bear against the other of said levers and cause the movement thereof as said throttle control is moved towards said full choke position, and resilient means effective upon movement of said throttle control toward said stop position to move said other trip lever into engagement with said starting means.

7. A control mechanism for a gasoline engine, wherein said engine includes a spring operated starting mechanism and a throttle control movable between stop and full choke positions, comprising: a lever operatively connected to said throttle control and movable between first and second limit positions corresponding to said stop and full choke positions, respectively; and control means operatively 7 connected between said throttle control and said starter mechanism so as to move into engagement with a portion of said starter mechanism when said lever is moved to said first limit position, enabling the tensioning of said spring against said portion of said starter mechanism, and so as to move out of engagement with said portion of said starter mechanism when said lever is moved from said first limit position towards said second limit position enabling said spring-tensioned portion of said starting mechanism to start the engine.

References Cited in the file of this patent UNITED STATES PATENTS Waite et al Aug. 15, 1939 Collins Apr. 30, 1945 Cicero et a1 Feb. 11, 1958 Fuchs et a1 Jan. 31, 1961 Thomas Sept. 5, 1961 FOREIGN PATENTS Great Britain June 10, 1959 

1. A CONTROL MECHANISM FOR AN IMPULSE STARTED GASOLINE ENGINE, WHEREIN SAID ENGINE INCLUDES A THROTTLE CONTROL MOVABLE BETWEEN STOP AND CHOKE POSITIONS AND WHEREIN SAID STARTER INCLUDES A ROTATABLE STARTING PLATE, A COIL SPRING, AND A SPRING TENSIONING DEVICE COMPRISING: A RELEASE LEVER ROTATABLY MOUNTED ON SAID ENGINE AND EFFECTIVE IN ONE POSITION TO ENGAGE SAID STARTING PLATE AND PREVENT THE ROTATION THEREOF DURING THE OPERATION OF SAID SPRING TENSIONING DEVICE; AND A CONTROL LINKAGE OPERATIVELY CONNECTED BETWEEN SAID THROTTLE CONTROL AND SAID RELEASE LEVER, SAID CONTROL LINKAGE BEING EFFECTIVE TO POSITION SAID RELEASE LEVER AT SAID ONE POSITION WHEN SAID THROTTLE CONTROL IS IN SAID STOP POSITION, MOVEMENT OF SAID THROTTLE CONTROL FROM SAID STOP POSITION BEING EFFECTIVE TO OPERATE SAID CONTROL LINKAGE, WHICH IN TURN OPERATES SAID RELEASE LEVER OUT OF ENGAGEMENT WITH SAID STARTING PLATE, SAID TENSIONED SPRING BEING THEN EFFECTIVE TO CAUSE SAID STARTING PLATE TO ROTATE AND START THE ENGINE. 